Refrigerator insulation drying arrangement



United States Patent REFRIGERATOR INSULATION DRYING ARRANGEMENTLawrence- A. Philipp, Detroit,

Kelvinator Corporation, of Maryland Mich., assignor to Nash- Detroit,Mich., a corporation This. invention relates to refrigerating apparatusand more particularly to such temperatures are maintained.

ln refrigeratorsof the household type having multiple compartments andevaporators, one of the difficulties 'resides in keeping the cabinetheat insulation dry and therefor effective. is due to condensationoccurring within the cabinet walls of water vapor which entrainedin roomair, finds its way into the cabinet casing through clearances which areimpractical to seal, such as the clearance around the door latch handle,the joints of heat Instead of allowing the moisture vapor to condenseand wet the insulation, it has been proposed to take advantage of theprinciple of diffusion by arranging for flow of moisture vapor by vaporpressure differential from the vicinity of the insulation to thefreezing evaporator Where the moisture vapor is deposited as frost onthe evaporator for removal at the time of defrosting of the evaporator.However, to keep the insulation dry by diffusion andipan ticularly inrefrigerators having freezing and cooling evaporators for separatemultiple compartments entails problems of moisture flow especially insuch arrangements where the freezing evaporator is exposed toadjacentcabinet insulation. In addition, there exists the problem of controllingor distributing moisture flow to surfaces of the freezing evaporatormoisture flow from all points within the cabinet walls to the freezingevaporator.

Accordingly, it is an object of my invention. to provide for arefrigerator of the type having a food storage compartment evaporatoranda freezing compartmentevaporator, an improved arrangement for' directingthe flow of moisture vapor by diffusion. from the insulation about thefood storage compartment to the freezing evaporator for deposit as frostthereon.

Another object of the invention is to provide an improved arrangementfor directing and distributingvapor moving by diffusion to areas of thefreezing evaporator to the end of inducing all moisture throughout tliecabinet walls to flow to the freezing evaporator.

Another object of the invention resides in enclosing the insulationaround the freezing evaporator and sealing it so that no moisture canreach the insulation and arranging for flow of moisture from theinsulation around the food storage compartment liner to the freezingevaporator.

A further above mentioned character embodying the principle of diffusionto keep the cabinet insulation dry and at the same time provide fordrainage of moisture during. defrosting without wetting the insulation.

More specifically, it is an object of my 'invention to' provide uprightwalls extending between the insulation of the food storage compartmentabove a freezer drip pan forming passages for passage of moisturelad'e'n. air to the freezer and arranging drip deflectors on 'saidlwallsto divert water, during defrosting, into the drip pan.

As is well known, wetting of the insulation breaker finish strips etc;v

such that there will. be

object is to provide a refrigerator of the apparatus in which multiple--denser 50 in the Further objects and. advantages of the presentinventionwill be apparent from 'the following description, reference being had tothe accompanyingdrawings, wherein-a preferredform of the invention isclearly shown.

In the drawings:

- Fig. l is a front view of a refrigerator having parts of the cabinetbroken away to show the interior thereof, and embodying features of myinvention;-

Fig. 2 is a vertical sectional view of an upper portion of. therefrigerator;

Fig. 3 is an'enlarged fragmentarysectional view of the refrigerator,taken along the line 3-3of Fig. 2;

i Fig. 4 is an enlarged fragmentary sectional view of the refrigerator,taken along the line 4-4 of Fig. 2;

Fig. 5 is a vertical sectional view of a detail of therefrigerator; and

Fig. 6 is a diagrammatical view of system. o-f'the refrigerator.

Referring to the drawings by characters of reference, the refrigeratorincludes a cabinet, designated in general by the numeral 20, having afood storage compartment 22-and a freezing compartment 24. In thepresent arrangement, the freezing compartment 24 is located vertically.above the food storage compartment, but maybe located below the foodstorage compartment, if desired. Access is gained to the cornpartments22 and 24 at the cabinet front which may be closed by a suitable door28. The cabinet 20 includes a sheet metal casing 30 and. a box-likesheet metalliner 32 of which. the latter forms the inner wall surfaces.of the food. storage cornpartment 22-. Heat insulation 34 is providedbetween the casing side, rear,: and bottom: walls and the correspondingwalls of. the liner 32 to'decrease heat leakage into the foodstoragecompartment 22.

The. freezing compartment 24 is refrigerated to a low desirable freezingtemperature by a refrigerant evaporator 36 of a primary refrigeratingsystem, and the food storage. compartment 22 isi cooled to*the desiredabove freezing temperature by a refrigerant evaporator 3801: a secondaryrefrigerating system. 'I'he'freezing evaporator 36 is-disposed withinthe. freezing compartment 24, andthe coolingevaporator 38 preferablyinthe form of a coil or. conduit is attached to the outer wall. surfaceof liner 32 in good heatconducting relation therewith.

As is illustratedin Fig.6, the" primary refrigerating system includesthe freezing evaporator 36, a refrigerant motor compressor unit 40, and.a refrigerant condenser 42. The outlet. of the motor-compressor unit ,40is connected by a conduit 44 to the. inlet of the condenser 42 whichhas.its outlet connectedin communication with the inletof evaporator 36 bya" smalldiameter or'capillary tube. 46. The tube 46 conductsliquidrefrigerant from the condenser 42' and meters the liquidrefrigerant so that theproper. amount of refrigerant is supplied to theevaporator tomaintain desired refrigeration. Connecting the capillarytube 46 and theinlet of evaporator 36 is a heat exchanger evaporatorcoil 48 which is arranged in heat conducting relation with a heatexchanger conform of a container. The secondary system evaporator 38 hasan inlet end 52 andian outlet end 54 connected to and in communicationwiththe heat exchanger condenser 50 wherein heattremoved from the foodstorage compartment by the secondary system is absorbed. by therefrigerant of theprimary systemiat the heat. exchanger evaporator 48.On the back of the freezing. evaporator 36 is a refrigerant accumulator56 from which refrigerant vapor is. withdrawn and returned to themotoncompressor unit 40 through a return conduit 58;

The evaporator 36 comprises a container 60' and a refrigerant evaporatoror coil 62. The container60 eX- tends across the cabinet substantiallythe width of the food storage compartment 22 and from front to back ofthe cabinet to provide a large freezer chest for storage of foodstuffsto be frozen. In the present arrangement, the evaporator coil 62 iswrapped around the container 6%, and extends along the top, bottom, andsides thereof in good heat conducting relation therewith but, othertypes of low temperature evaporators may be used. Brackets (not shown)may be used to mount the evaporator 36 on the cabinet casing 30. Themotor-compressor unit 40 and condenser 42 may be located in the lowerpart of cabinet 29 in the usual manner.

Heat insulation is provided between the freezing evaporator as and thecasing 30 and to avoid wetting of the insulation, I encase the same inmoisture impervious enclosures or envelopes 64. This bagged heatinsulation is interposed between the corresponding walls of the easing39 and the freezing evaporator as and between the bottom of theevaporator 36 and the top of the food storage compartment liner 22 suchthat, except for its front, the evaporator 36 is encased in baggedinsulation. The insulation envelopes 64 may be made of resinous plasticmaterial such as polyethyline plastic sheet and be sealed by theapplication of heat to melt the plastic material at and seal the jointsof the envelopes. Preferably, the top and side envelopes 64 ofinsulation are spaced from the evaporator 36 to provide spacestherebetween for frost to form on the evaporator 36. To this end Iprovide a spacer 68 comprising a horizontal panel 7% overlying the topof the evaporator 36 having depending sides '72 which overliecorresponding evaporator sides and extend down substantially the bottomof the evaporator 36. Secured to and on the underside of the panel 7%are spacer members 74 preferably of low heat conducting material whichrest on the top of the evaporator 36 to space panel 70 therefrom.Carried by and secured to the inner surfaces of the panel sides 72 arespacer members 78 for spacing the side panels 72 from the sides of theevaporator 36. Preferably, the spacer panels are made of a waterrepellant material, such as waxed, heavy cardboard.

Spaced below the evaporator 36, the lower insulation envelope 64 restson the top wall of the food storage compartment liner 22, and resting onthe insulation is a drip pan fill. The drip pan 30 is a sheet metal panwhich extends substantially from front to rear of compartment 24 andextends beyond the sides of evaporator 36 to the sides of the spacerpanels 72 to catch all drip from the evaporator and any moisture whichmay run down the inner surfaces of the spacer panels 72..

In accordance with my invention, I provide for keeping the insulation 34dehydrated by a particular arrangement of a plurality of passages 82which connect the space between liner 32 and casing 30 for flow of watervapor by diffusion to the evaporator 36 for deposit as frost thereon. Tothis end, I provide upright wall members 84 extending upwardly from thesides of liner 32 to the freezing compartment 24 having the verticalpassages i-Z which establish communication between the insulation 3:4and the freezing evaporator 36. Also, the wall members 84 extendsubstantially from the trimbreaker strips rearwardly substantially thedepth of the liner 32 to provide moisture vapor flow throughout theinsulation 34 of the cabinet side walls and to provide distribution ofthe vapor over the entire side areas of the evaporator sides.

To further increase vapor flow passage capacity, I provide along each ofthe upper side edges of the liner 32, a horizontal passage 38 which runsfrom front to rear of the liner 32 in communication with the insulation34 and with passages 82. The passages 88 may be provided economically bywelding or otherwise securing storage compartment to the angle members90 to the top and sides of the liner as illustrated in Fig. 2. In thehorizontal legs of the angle members 90 is a plurality of outletapertures 92 communicating with the insulation receiving space betweenthe top wall of liner 32 and the drip pan 8t and the horizontal passagesA plurality of water vapor inlets 94 are provided in the vertical legsof the angle members for flow of water vapor from insulation 34 into thehorizontal passages 83. By diffusion, water vapor flows from the highpressure vicinity of the insulation 34 up through passages 82 to thefreezing evaporator 36 and other water vapor flows by diffusion from thevicinity of the insulation 34 through inlets 94 into the horizontalpassages 83 whence the moisture vapor flows out of outlets 92 and uppassages 32 to the evaporator 36. Thus, water vapor which leaks into thecabinet entrained in the room air is deposited as frost onto thefreezing evaporator 36 instead of wetting and consequently rendering theinsulation 34 ineffective.

The wall members 34 may be economically fabricated of heavy, waxedcardboard and may comprise a corrugated sheet 96 and a backing sheet 95.These sheets may be clipped, stapled or be otherwise secured together toform the passages 82. At its top, each of the wall members 84 isprovided with an inwardly directed flange 100 which extends into thespace between the lower edge of the spacer panels 72 and the drip pan80. The tops of the wall members or flanges 1% are inclined downwardlytoward the drip pan 80 so as to drain moisture thereinto.

Secured to the rear wall of the food storage compartment liner 32 is apair of vertical channels 102 which form passages 104 for the passage ofmoisture vapor from the rear wall insulation to the evaporator 36. Thechannels 1'62 extend upwardly from points adjacent the bottom of theliner 32 to the space between the bottom of the freezing evaporator 36and the drip pan fill. The secondary system evaporator 33 on the rearwall of the liner 3?; spaces the channels from the liner wall so thatvapor throughout the insulation space of the rear wall can flowlaterally into the channels 102. The drip pan 80 may be provided with asuitable drain (not shown).

From the foregoing description, it will now be understood that I haveprovided a new and improved arrangement to effect vapor diffusion andpassage of water vapor from the spaces occupied by the insulation of thefood freezing evaporator whereon the moisture deposits and is frozen tothe end of keeping the insulation dry and therefore effective.Furthermore, it will be noted that I have effected flow of water vaporfrom between the side walls of the liner and casing by the provision ofpassage forming means which is so constructed as to increase flow to thefreezing evaporator. Also, I have provided a new and improvedarrangement of passage forming means for conducting water vapor to thefreezing evaporator including a large flow capacity distributed over anarea such that all insulation is dehydrated. In addition, I haveprovided wall means which form passages for conducting water vapor tothe freezing evaporator and also function to deflect water drip into adrip pan beneath the freezing evaporator.

Although only a preferred form of the invention has been illustrated,and that form described in detail, it will be apparent to those skilledin the art that various modifications may be made therein withoutdeparting from the spirit of the invention or from the scope of theappended claims.

I claim:

1. Refrigerating apparatus comprising, a cabinet casing having sidewalls, a liner within said casing forming a food storage compartment andhaving side walls spaced from the casing side walls, a refrigerantcooling evaporator cooling said compartment, a refrigerant freezingevaporator within said casing externally of said liner, heat insulationbetween said freezing evaporator and said casing and between saidfreezing evaporator and said liner, second heat insulation between saidliner and easing side walls, opposite side wall means spacing said firstinsulation from the sides of said freezing evaporator, a drip and airbaffle plate beneath said freezing evaporator between said freezingevaporator and the first insulation between the freezing evaporator andsaid liner, said baflie plate being spaced from the lower edges of saidopposite side wall means, upright wall means forming air flow passagesestablishing communication between the space between said liner andcasing and said freezing evaporator for diffusion of vapor, and means onsaid wall means to direct defrost Water onto said baflle extendinglaterally between the lower edges of said wall means and said plate.

2. Refrigerating apparatus comprising, a cabinet casing, a box-likeliner within said casing forming a food storage compartment, a coolingelement within said casing externally of and cooling said liner, asecond liner within said casing spaced from said first liner and forminga freezing compartment, a cooling element refrigerating said secondliner and disposed between said second liner and said casing, heatinsulation in the space between said liners, moisture imperviousmaterial enclosing said insulation, heat insulation in the space betweensaid second liner and said casing, a drip pan supported on said moistureimpervious material below said second evaporator, moisture imperviousmaterial enclosing said second insulation, insulation in the spacebetween said first liner and said casing, wall means npported by saidlast-named insulation against one edge of said first insulation having aplurality of upright ducts establishing communication between saidlast-named insulation and said secondnamed insulation, said plurality ofducts having outlets open to the space between said drip pan and saidsecond cooling element for passage of water vapor from said lastnamedinsulation to said second-named insulation to said second named coolingelement, and angle members cooperating with corners of said box-likeliner forming passages in communication with said last-named insulationand with said ducts to conduct water vapor to said second coolingelement.

References Cited in the file of this patent UNITED STATES PATENTS 202,515,892 Philipp July 18, 1950 2,576,665 Bixler Nov. 27, 1951 2,672,030Schweller Mar. 16, 1954

